Remote control



G. A. WALDIE 2,418,532 mum's common Filed larch 10, 1943 2 Sheets-Sheet1 v INVENTOR czoaczmwum;

ATTORNEYS Patented Apr. 194? REMOTE Contact v George A. Waldie, Edison;Ohio, assl'gnor to The V Hydraulic Development Corporation, 1nc.,Wll-

mington Bet, a corporationoiDeiawai-e Application March 10, 1943, SerialNo. 478,643 7 so Claims. (01. 103 -38) This invention relates to controlsystems and;

in particular, to control means for remotely controlling a reciprocablemember such as the flow control member of a variable delivery pump.

While heretofore known control systems of a this type vrequiredmechanicaL.hydro-mechanical or electrical transmitting means between thecon-' It is another object to provide a remote control system for afluid source of variable deliv-=.

ery including a reciprocable flow control memher, in which the pressurefor bringing about a movement of the reciprocable control member may beremotely controlled by means connected with said reciprocable member. bypurely hydraulic means. a

Another object of this invention consists in the provision of a remotepressure control system for a pressure fluid source of variabledelivery, in which variations in pressure at the delivery side of saidfluid source are hydraulically transmitted to a control mechanism whichin its turn brings about a variation in the deliveryof the fluid source.7

It is a still further object of this invention to provide a remotepressure control system for a fluid source or variable delivery, inwhich mechanically adjustable control means, remotely ar ranged fromsaid fluid source and connected thereto by hydraulic means only, isadapted auto matically to bring about a variation in the delivery ofsaid fluid source in response to a predetermined variation in pressureat the pressure side of said fluid source. I

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with the accompanying drawings, in which:

Figure l diagrammatically illustrates a first embodiment of a controlsystem according to the present invention.

Figure 2 is an enlarged section along the line 2-2 of Figure l. V

Figure 3 is an enlarged view along the line 3-3 of Figure 1.

Figure 4 is a diagrammatic illustration of the principle of operation ofthis invention.

Figure 5 diagrammatically illustrates a control system according to asecond embodiment of the invention.

to actuate the same.

Figured is a graph illustrating the variations I oithe controlpressures. l 1 p Referring now to the drawings, and Figures 1 to 3 inparticular, the system shown therein comprises a variable deliverypumpof any standard design which has connected thereto a caslngll with afluid operable plunger l2 reciprocably mounted therein. The plunger I2is adapted in response to fluid pressure acting thereupon to engage theflow control member or the pump ID and Connected to the casing ii is apilot line 13' which leads to the pressure line H. The pressure line Hmay be connected to the pressure side of a fluid operable motor of anystandard design. Alsoconnected to the pump 10 is a control cylinder l5having reciprocably mounted therein a plunger l6, which latter iscontinuous- 'ly urged into engagement with the flow control member ofthe pump Ill by means of a spring II. The spring i1 acts through theplunger. IS on the flow controlmember of the pump I0 so as to conthroughconduit M with a fluid reservoir or tank i9; Also connected with thetank 59 is a conduit it which may be connected to the exhaust line ofthe above mentioned fluid operable" motor.

Connected to the conduit-20 is a line, leading to a rotary valve,generally designated 22. This rotary valve comprises a rotary valvemember 23 longitudinal bore 29 therethrough which is in. fluidcommunication with the conduit 2| and also with a passageway to in thevalve member 23.

The passageway 30 in the valve member" communicates through a conduit 3!"with the control cylinder t5. The cut-out portions 24 and 25, which areinterconnected through the grooves 2i and 28, for balancing the valvemember 23, and the passageway 38 are adapted hydraulically tocommunicate with the conduit 3| leading to the control cylinder i5. Theannular groove 26 in the valve member 23 is connected through theconduit 32 with the pressure line H and is furthermore connected througha conduit 33 with a cylinder 35 provided in a' control device, generallydesignated 35.

Reciprocably mounted in the cylinder 3 4 is a plunger 36 which hasconnected thereto '2. scotch yolse iii. The yoke 37 engages a pin 38which is eccentrically connected to a flange 39 on an extension 40 ofthe valve member 23. It will be clear that movement of the plunger 33 inlongithe right. Due to the connection of the pin 38 tudinal directionwill impart a rotative movement to the flange 39 and thereby the rotaryvalvev member 23.

The yoke 31 has connected thereto and 40a I which has adiustably mountedthereon a collar 4|. The collar 4| is engaged by one end or a spring 42,the other end of which engages a screw 43 through which passes the rod40a. The screw 43' which threadedlyengages the closure member 44 of thecontrol device 35 has connected thereto a knurled head 45' which isengaged by an adiustable nut 43 threaded upon the end of the rod 40a.-The position of the nut 46 determines the extreme left hand position ofthe plunger 36.

Before describing the operation of the system shown in Figures 1, 2 and3, the essenceof the invention may be briefly referredto by reference ato Figure 4. This figure shows two adjustable chokes 41 and 48 which areinterconnected as indicated by the dot-dash line 49. The interconenection is-such that if the opening in one choke is increased theopening in the other choke is decreased. It will, therefore, be clearthat when the pressure drop across the choke 41 increases, 7

the pressure drop across the choke 43 will decrease.

The opening in the choke 41 corresponds to the free fluid connectionbetween the cut-out portion 24 and the conduit 3|, whereas the openingin the choke 48 corresponds to the free fluid connection between thepassageway 30 and the conduit 3|." The rotation oi'the valve member 23from the position shownin Figure 2 in the direction of the arrow A willtherefore increase the way 30 and from there into the conduits 2| and20. This results in a pressure drop in the conduit 3| and therefore alsoin the cylinder I5. Therefore, the balance of pressure on both sides ofthe flow control member pertaining to the pump i0 is disturbed in viewof the pressure acting on the plunger |2 so that the latter moves theflow control member of the pump ID to the left as seen in Figure 1 inflow. reducing direction against the thrust of the sprin If the pressureincrease in the conduit M and therefore also in the conduit i3 and thecasing H is sumfree fluid connection between the passageway 30 and theconduit 3| while simultaneously restricting the fluid connection betweenthe conduit 3| and the cut-out portion 24.

Referring now again to Figure 1, and assuming that all elements of thehydraulic system occupy the position shown therein, the device operatesasiollows: I It may be assumed that the pump I0 is delivera ing pressurefluid into the line I4 from where the fluid passes to the pressuresideof a hydraulic motor. The pressure prevailing in conduit |4isconveyed through conduits 32 and 33 into the cylinder 34 where it actsupon the plunger 33 and sure acting upon the plunger 33 is balanced bythe spring 42. 'It may also'be' assumed that in this balancing position,the valve member 23 occupies the position shown in Figure 2. A portionof the fluid delivered by the pump l0 into the conduit 32 will then passthrough the annular groove 28 and ciently high, it will move the pump Into substantially neutral or no delivery position. When the pressure inthe conduit |4 drops again, the pressure in the casing II will likewisedrop and the spring I! will again move the flow control member of thepump in in flow increasing direction.

To vary the pressure required in the cylinder 34 for bringing about adesired rotation of the valve member 23, it is merely necessary toadjust the screw 43, thereby varying the thrust of the spring 42. Thestarting position from which the valve member 23 will rotate may bevaried by varying the position of the nut 46.

While the system shown in Figure 1 has been described as a pressurecontrol system, the arrangement oif'Figure 1 may also be used forovercoming temporarily increased resistance as it is sometimesencountered with machine tools. To make the system of Figure l adaptablefor this purpose, it is merely necessary to eliminate the l pin 38 andsubstitute therefor the pin indicated in dot-dash lines. It will then beclear that when the pressure in the conduit l4 due to increasedresistance should increase, this pressure will act through conduits 32and 33 on the plunger '36 and move thesame toward the right to bringabout rotation of the valve member 23 in' clockwise direction withregard to Figure 2. This will moves the same into a position in whichthe presthe longitudinal groove 21, the cut-out portion 24 and fromthere in part through conduit 3| into the cylinder l5 where it acts upontheplunger-l6. The fluid pressure thus acting upon the plunger l8 plusthe pressure exerted by the spring I! are balanced by the pressureconveyed from the pressure line l4 through conduit l3 to the plunger12.: Another portionof the fluid in the cut-out portion 24 passesthrough conduit 3|, passageway 30, bore. "and conduit 2| into theconduit 20.

. It now, for some reason, it should occur that theresi'stanceencountered bythe said motor increases so that also thepressure in the conduit l4 and therefore also in the conduit 32increases, this pressure will be conveyed through the conduit 33 to thecylinder 34. Here thepressure will act upon the plunger 38 and move thesame toward increase the fluid connection between the cut-out portion 24and conduit 3|, while decreasing the fluid connection between theconduit 3| and the passageway 30. v

Therefore, the pressure in conduit 3| will increase and move the pump IDin delivery increasing direction. Consequently, a. greater quantity orfluid will be delivered by the pump 10 into the conduit H which will beadapted to meet the increased resistance; When the resistance 'has beenovercome, the pressure in conduit I4 will drop again so that also thepressurein the cylinder 34 will decrease andthe spring 42 will move thevalve member 23 in anti-clockwise direction. This will restore theoriginal conditions.

, It should be noted that in the operation just described, the increasein pressure in the'cylinder l5 due to the rotation of the valve member23 in clockwise direction will be higher than'the increase in pressurein the casing plunger 36 and the valve member 23.. r

Referring-now to Figure 5, thesystem shown therein makes use of the sameprinciple described This isdue to the ratio of transmission between thein connection with Figures l-to 3. According to Figure 5, apressurefluid source of variable delivery such as the pump is provided. Thepumpv the pump 5| into full a' plunger 55 adapted. in response toapredeterj mined pressure acting thereupon to move the pump 5| into flowreducing directionagainst the thrust of the spring 54. Connected to thecylinder 55 is a conduit 51 which leads to a control device, generallydesignated 58. a v

The device 58 comprises a cylinder 59 closed at each ,end and havingreclprocably mounted therein a valve member, generally designated 60.The valve member 50 includes two spaced pistons BI and 62 reciprocablymounted in a bore 63 While the outer diameter of the piston 5|corresponds substantiallyto the inner diameter of the bore 63, thepiston 62 has a smaller diameter so that a cylindrical space 64 isformed between the piston 62 and the adjacent portion of the bore 63adapted to allow fluid communication between the bore portion locatedintermediate the pistons BI and 52 with that portion of the bore 53which is located between the lower end of the bore 83 i and the piston62. j

The cylinder 59 is provided with three spaced annular grooves 65, 66 and61. The annular groove 65 is connected through a conduit 58 with thepressure line 69 interconnecting the pressure "side of the pump 5| withthe pressure side of a hydraulically operable motor not shown. Thegroove 65 communicates through the conduit. 51 with the cylinder 55,while the groove 61 is connected through a conduit 10 with the tank orfluid reservoir H. The tank 1| is connected substantially neutral or nodelivery position. The pressure which will act upon the plunger 55 willbe dependent the upper surface 19 of the piston 52 and the annulargroove 66. Therefore, changing the distance between the surface 19 andthe groove 55, by rotating the head 16 will vary the pressure requiredfor moving the plunger 58 in flow re-- .stricting direction.

The result of the adjustment of the valve member 60 can be read from thegraph in Figure 6.

" In this figure, the ordinate indicates the control f pressure, i.

e, the total pressure drop from the.

surface 19 to the surface 80. whereas the alt-- scissa indicatesthesettingof the scale-11.

The, particular control position shown in Figure 5 is illustrated inFigure 6 by the curve scope of the appended claims. 1

through a llne'12 with the exhaust port of the above mentioned fluidoperable motor.

. The tank! I is furthermore connected withthe suction side of thepump'jfil through a conduit 13. The valve member 6|! is also' providedwith a threaded extension 14 which threadedly engages the closure member15 of the cylinder 59 and is adjustable from the outside of the cylinder59 so as to selectively movethe valve member upwardly or downwardly.

- The extension to which the-valve inember 6|) downwardly by rotation ismoved upwardly or of the knurled head 15 can bechecked on the scale 11provided on an extension 18 of the valve member 50 which scale extendsto the outside of the cylinder.

-.:The device cit-Figure 5 operates as follows: ,It may assumed that thepump 5| has been ahiited iiito lull stroke position by the springlkand-jnpwbegins to deliver pressure fluid into ,fthe'pressure' line 69.Soon pressure begins to idevelcp lnjthe line 59 which pressure is con-"jvei edihroucn conduit to to the bore ea. Here pu ls!!! fluid passesthrough the cylindrical "It-lief, .portionzil between the upper surface19 of the *pistbll' fl and the annular groove 85.

' this fluid enters the conduit 51, a predetermined pressure drop willhavetaken place. :However, pressure still prevails in the conduit *5!which pressure will act upon the plunger and counteract the spring 55 tothereby bring about reduction of the delivery of the pump 5|. If thepressure acting upon the plunger 55 is gutflclently high, the pump 5|will be moved to I claim as new and desire MNOP. The line ON indicatesthe place of the annular groove 56 withrespect to the upper and lowersurfaces 19 and 80, respectively, of the valve member 52. It will,therefore, be clear that in the graph of Figure 6, MQ indicates thepressure drop between the surface 19 and the annular groove 55, whereasthe line QR indicates the pressure drop between the'annular' groove 55and the surface 80. r

The graph of Figure 6 thereforamakes it possible to find the pressuredrop between the surface 19 and the groove 55 and also between thegroove 66 and the surface 80 for any desired positicn of the valvemember 60, thereby enabling a proper gaging of the scale 11.

It is, of course, understoodthat the present invention isby no meanslimited to the particular structure shown in the drawings but embracesany modifications which come within the Having thus fully described myinvention, what Patent isz,

1. In combination, a variable delivery pump having control means forvarying the delivery,

yielding means for continuously urging said control means in deliveryincreasing direction, fluidoperable plunger means likewise associatedwith said pump'control .means and operable thereon selectively to movesaid livery of the pump, and choke means lically connected between thedelivery side of saidpump and said plunger means and adapted in responseto a predetermined pressure at the to causesaid plunger v delivery sideof said pump means to reduce the delivery of said pump.

2. In combination, a fluid source of variable delivery, delivery varyingmeans associated with said fluid source for selectively increasing orreducing the delivery thereof, yielding means associated with saiddelivery varying means and continuously tending to increase the deliveryof said source, and choke means connected to said delivery varying meansby hydraulic means only,- said choke means being the delivery side'ofsaid delivery varying means said fluid source'at a predeterminedpressure depending on the setting of said choke means.-

3. In combination, a variable delivery pump, means continuously urgingsaid pump into full delivery position, a first and an opposed secondplunger of substantially equal areas, said first plunger being directlyconnected with the pressure side of said pump and being adapted toreduce the delivery of said pump against the thrust of said urgingmeans, pressure responsive choke means hydraulically connected with theon the pressure drop between to secure =by"Lettera means to vary thedehydram' responsive, to pressure at fluid source to cause said toreduce the delivery of second plunger, and

- delivery position,

fluid pressure responsive means hydraulically connected with thedelivery side of said pump for adjusting said chokemeans in response toa predetermined pressure at the delivery sideof said fluid source tothereby reduce the pressure on said second plunger, thereby causing saidfirst plunger to reduce the delivery of said fluid pump.

4. Incombination, a variable delivery pump,

means for continuously urging the delivery control of said pump intofull delivery position, a first and an opposedsecond plunger ofsubstantially equal areas, said first plunger being directly 7 connectedwith the pressure side of said pumpand being adapted to reduce thedelivery of said pump against the thrust of said urging means, fluidpressure responsive choke means hydraulically connected between thesecond plunger and the delivery side of saidipump, and means foradjusting the actuating pressure for' said fluid pressure responsivemeans.

5. In combination, a variable delivery pump,

resilient means for continuously urging the delivery control of saidpump into full delivery position, plunger means operatively connectedwith the delivery control of said pump and nected with the delivery sideof said pump and having another side connected with said plunger meansto thereby cause the latter in response to a predetermined pressure atthe delivery side of said pump to reduce the delivery thereof.

.6. In combination, a pump of variable delivery, yielding means forcontinuously urging the delivery control of said pump into full deliveryposi tion, plunger means operable by pressure fluid and associated withthe control means of said pump for reducingthe delivery of said pump inresponse to a predetermined pressure on said plunger means, pressurecontrol means including a cylinder hydraulically connected with thedelivery side of said pump, and a control piston adjustable in saidcylinder and having an outer diameter less than the inner diameter ofsaid cylinder so as to create a pressure drop between the ends of saidpiston, and means hydraulically connecting a point between'the ends ofsaid piston with said plunger means.

7 In combination, a pump of variable delivery,

livery control of said tion,

pump into full delivery p'osiplunger means' operable. by pressure fluidandhassociated with the control means of said pump for reducing thedelivery of said pump in response to a predetermined pressure on saidplunger means, pressure control means including a cylinder hydraulicallyconnected with the delivery side of said pump, and a control pistonadjustable in said cylinder and having an outer diameter less than theinner diameter of said cylinder so as to create a pressure drop betweenthe ends of said piston, means for hydraulically connecting a pointbetween the ends of said piston with said plunger means, and means foradjusting said piston to vary the position of said point.

8.In combination, a variable delivery pump, means continuously urgingsaid pump into full pressure-actuated plunger means'having a first and asecond opposed area for controlling the delivery of said pump, saidflrstarea being directly connected with the dehvery side of said pump.Pressure-actuated choke adapted selectively to reduce the delivery ofsaid pump against the thrust of said resilient means, and choke meanshaving one side thereof con-' means hydraulically connected with saidsecond area, and fluid pressure responsive means hydraulically connectedwith the delivery side of said pump and connected to vary the chokesetting in response to a predetermined pressure at the deliveryside of.said pump.

9. In combination, a fluid source having variable delivery controlmeans, yielding means urging said control means to full deliveryposition,

pressure responsive means coacting with said yielding means to vary thedelivery of said source, and a connection between the output of saidsource and said responsive means, including means of applying to saidresponsive means a pressure which is a predetermined fractional part ofthe pressur of said output.

10. In combination, a source of fluid having variable delivery controlmeans, means continuously urging said control meanstoward full deliveryposition, pressure responsive plunger means connected to be actuated bypressure from said fluid source and operable to vary the eflect of saidurging means to thus vary the delivery of said controlling means againstthe action of said urging means to effect a, change in the delivery ofsaid source, and means connected to be responsive to the deliverypressure of saidsource to establish a control pressure which is apredetermined fractional part of said delivery pressure, and a fluidconnection'connecting said control pressure and said deliverycontrolling means yielding means for continuously urging the detosupplement the action 01 said urging means.

12. In combination, a fluid source having delivery control means,pressure responsive means operable on said control means to vary thedelivery of said source, a flow restrictor connected to pass fluid fromthe discharge side of said source, and means hydraulically connectingsaid pressure responsive means with said flow restrictor between theinlet and outlet'thereof for receiving pressure therefrom.

13. In combination, a fluid source having delivery control means,yielding means continuously urging said control means toward fulldelivery position, pressure responsive means oper- I able on saidcontrol means to vary the delivery of said source, a flow restrictorhaving its inlet connected to the discharge side or said source to passfluid therefrom to its outlet, and means hydraulically connecting saidpressure responsive means with said flow restrictor between the inletand outlet thereof for receiving pressure therefrom which is apredetermined fraction of the discharge pressure of said source.

14. In combination, a fluid source having delivery control means,pressure responsive means operable on said control means to vary thedelivery oi! said source, a flow restrictor having its inlet connectedto the discharge side of said source to pass fluid therefrom to itsoutlet, means hydraulically connecting said pressure responsive meanswith said flow restrictor between the inlet cause a reduction in A a,and outlet thereof, and means for adjusting the effective hydraulicposition of said last mentioned connection between the said flowrestrictor inlet and outlet.

15. In combination, a fluid source having delivery control means, fluidpressure responsive means operable on said control means to vary thedelivery of said source, first and second flow restricting meansserially connected between the discharge side of said source and a pointof lower pressure to pass fluid from said discharge, and meanshydraulically connecting said pressure responsive means to be actuatedin response to the pressure between said restricting means.

16. In combination, a fluid source having delivery control means, fluidpressure responsive means operable on said control means to vary thedelivery of said source, first and second flow restricting meansserially connected between the discharge side of said source and a pointof lower pressure to pass fluid from said discharge, and means foradjusting at least one of said restricting means to vary the pressurewhich actuates said pressure responsive means.

17. In combination, a fluid source having delivery control means, fluidpressure responsive means operable on said control means to vary thedelivery of said source, first and second flow restricting meansserially connected between the discharge side of said source and a pointof lower pressure to pass fluid from said discharge, and means operablesimultaneously to adjust both oi, said restricting means to vary thepressure therebetween and thereby to vary the pressure to which saidpressure responsive means is responsive.

18. In combination, a fluid source having delivery control means, fluidpressure responsive means operable on said control means to vary thedelivery of said source, first and second flow restricting meansserially connected between the discharge side of said source and a pointof lower pressure'to pass fluid from said discharge, and means operableinversely and simultaneously to adjust said restricting means forvarying the pressure therebetween and thus to vary the dischargepressure of the source which is efiective to actuate said pressureresponsive means.

19. In combination, a fluid source, delivery con trol means associatedwith said source, pressure responsive means operable on said controlmeans to vary the delivery of said source, flow restricting meansconnected between the discharge side of said source and the exhaust topass fluid'from said discharge, means hydraulically connecting saidpressure responsive means with a point on said flow restrictor betweenthe inlet and outlet thereof, and fluid pressure responsive meansconnected to be responsive to the discharge. pressure of said source andoperable automatically for varying the effective hydraulic position ofthe connection of said pressure responsive means with said flowrestrictor.

20. In combination, a fluid source having delivery control means,pressure responsive means operable on said control means to vary the delivery of said source, a first and a second flow restricting meansconnected to pass fluid from the discharge side of said source inproportion to the pressure thereof, conduit means hydraulicallyconnecting said pressure responsive means to be actuated in response tothe pressure between said restricting means, and means connected withthe discharge side of said source and responsive to the pressure thereoffor simultaneously adjusting said flow restricting means one in theincreasing direction and one in the decreasing direction to vary theactuating pressure for said pressure responsive means.

GEORGE A. WALDIE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,908,534 Parsons May 9, 19332,032,430 Muller Mar, 3, 1936 2,248,076 Harrington July 8, 19412,238,063 Kendrick Apr. 15, 1941 2,238,061 Kendrick Apr, 15, 19411,870,501 Ernst Aug. 9, 1932 2,333,530 Ernst Nov. 2, 19%

